The protein(s) encoded by the c-myc locus and the c-ets locus has been examined in human cell lines and will be isolated from those cell lines which show these proteins to be amplified. To probe these proteins, polyclonal or monoclonal antibodies were prepared against peptides representing derived amino acid sequences from the myc or ets DNA sequence. The ets-2 and myc proteins have been localized by subcellular fractionation. The ets-2 protein shows primarily nuclear localizations, while the myc proteins, in addition to showing nuclear localizations, also show cytoplasmic localization. The ets-2 p56 protein and the myc p58, p60 (cytoplasmic) and p80 (cytoplasmic) proteins have been partially or completely purified (myc p60). The N-terminal amino acid sequence or the myc p60 (cytoplasmic) has been obtained and is found not to correspond to the derived amino acid sequence of myc. This new protein may correspond of a family of myc-related proteins.